From 6dd4b1f1d026e478d9177b28169b377e212400f3 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Sun, 26 Feb 2017 23:44:11 +0100 Subject: [PATCH] 9pfs: local: improve error handling in link op When using the mapped-file security model, we also have to create a link for the metadata file if it exists. In case of failure, we should rollback. That's what this patch does. Signed-off-by: Greg Kurz Reviewed-by: Stefan Hajnoczi --- hw/9pfs/9p-local.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index 77f79b60ae..2538bd317d 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -920,6 +920,7 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath, int ret; V9fsString newpath; char *buffer, *buffer1; + int serrno; v9fs_string_init(&newpath); v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name); @@ -928,25 +929,36 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath, buffer1 = rpath(ctx, newpath.data); ret = link(buffer, buffer1); g_free(buffer); - g_free(buffer1); + if (ret < 0) { + goto out; + } /* now link the virtfs_metadata files */ - if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) { + if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { + char *vbuffer, *vbuffer1; + /* Link the .virtfs_metadata files. Create the metada directory */ ret = local_create_mapped_attr_dir(ctx, newpath.data); if (ret < 0) { goto err_out; } - buffer = local_mapped_attr_path(ctx, oldpath->data); - buffer1 = local_mapped_attr_path(ctx, newpath.data); - ret = link(buffer, buffer1); - g_free(buffer); - g_free(buffer1); + vbuffer = local_mapped_attr_path(ctx, oldpath->data); + vbuffer1 = local_mapped_attr_path(ctx, newpath.data); + ret = link(vbuffer, vbuffer1); + g_free(vbuffer); + g_free(vbuffer1); if (ret < 0 && errno != ENOENT) { goto err_out; } } + goto out; + err_out: + serrno = errno; + remove(buffer1); + errno = serrno; +out: + g_free(buffer1); v9fs_string_free(&newpath); return ret; } @@ -1189,14 +1201,12 @@ static int local_renameat(FsContext *ctx, V9fsPath *olddir, goto err_undo_rename; } - omap_dirfd = openat(odirfd, VIRTFS_META_DIR, - O_RDONLY | O_DIRECTORY | O_NOFOLLOW); + omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR); if (omap_dirfd == -1) { goto err; } - nmap_dirfd = openat(ndirfd, VIRTFS_META_DIR, - O_RDONLY | O_DIRECTORY | O_NOFOLLOW); + nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR); if (nmap_dirfd == -1) { close_preserve_errno(omap_dirfd); goto err; -- 2.11.4.GIT